Search by BoMiProt ID - Bomi162

Primary Information

BoMiProt ID Bomi162
Protein Name Mucin 1
Organism Bos taurus
Uniprot IDQ8WML4
Milk FractionWhey
Ref Sequence ID NP_776540.1
Aminoacid Length 580
Molecular Weight 58092
FASTA Sequence Download
Gene Name MUC1
Gene ID 281333
Protein Existence Status Reviewed: Experimental evidence at protein level

Secondary Information

Presence in other biological fluids/tissue/cells mammary, salivary, lung, pancreas, kidney and stomach
Protein Function integral membrane component; glycosylated molecule of MUCl on the surface of epithelia presents a physical barrier protecting the cell; anti-invasion characteristics;roles as a growth inhibitor; at digestion;protecting membrane proteins from protease action;being a large, extended membrane protein, it may shield other nearby residents.
Biochemical Properties rich in serine, threonine,proline, alanine and glycine; rigid, extended molecule due to random coil promoting properties of prolines and the further rigidity conferred by glycosylation; beneficial characteristic of MUCl is its relative durability, especially its resistance to proteases
Significance in milk MUCl may be a factor regulating size of MFGs, membrane secretion, and fat content of milk; sialic acid of mucins on MFGs prevent their clumping and clogging the ducts through which they must pass
PTMs glycoprotein; 50% carbohydrate, 30% of which was sialic acid; polymorphic and carbohydrate portion is of variable nature; serine and threonine hydroxyls provide sites for glycosylation; human milk MUC1 has high galactose, modest level of sialic acid, and lack of detectable mannose; bovine MUC1 has less galactose, significant mannose and much higher sialic acid; galactose and N-acetylglucosamine are the dominant sugars in the human mucin; O-linked oligosaccharides are comprised of a core unit attached to MUCl via N-acetylgalactosamine, a backbone, and a terminal region; The core and backbone may be branched and the ends may be terminated by sialic acid, galactose, fucose or N-acetylgalactosamine; Sulfation may also occur at the periphery;
Site(s) of PTM(s)

N-glycosylation, O-glycosylation,
Predicted Disorder Regions 28-359,544-563
DisProt Annotation
TM Helix Prediction 2TMHs; (7-29), (486-508)
Significance of PTMs The oligosaccharides carry substantial sialic acid at their termini and this accounts for two putative functions of this mucin, i.e., to keep ducts and lumens open by creating a strong negative charge on the surface of epithelial cells which would repel opposite sides of a vessel, and to bind certain pathogenic microorganisms; sialic acid content in terminal positions on oligosaccharides of the mucin confers a negative charge to the extracellular surface,that might prevent wall to wall adherence in lumens and ducts thus preventing their closure and preserving the integrity of secretory systems
Bibliography 1. Patton, S., Huston, G. E., Jenness, R., & Vaucher, Y. (1989). Differences between individuals in high-molecular weight glycoproteins from mammary epithelia of several species. BBA - Biomembranes, 980(3), 333–338.
2. Schroten, H., Hanisch, F. G., Plogmann, R., Hacker, J., Uhlenbruck, G., Nobis-Bosch, R., & Wahn, V. (1992). Inhibition of adhesion of S-fimbriated Escherichia coli to buccal epithelial cells by human milk fat globule membrane components: a novel aspect of the protective function of mucins in the nonimmunoglobulin fraction. Infection and Immunity, 60(7), 2893–2899. Retrieved from
3. Mather, I. H., & Keenan, T. W. (1975). Studies on the structure of milk fat globule membrane. The Journal of Membrane Biology, 21(1–2), 65–85.